JPH0968156A - Centrifugal pump pulsation suppression device and method - Google Patents

Abstract

(57) Abstract: The generation level of fluid pulsation is reduced, and the vibration response of a structure caused by pulsation is reduced. SOLUTION: Two vortex pumps 1 and 2 whose phases are controlled give the fluid pulsation in a tank 3 an opposite phase, and the pulsation level is reduced by superposing them. Pulsation measurement sensors 6 and 7 are installed in the pipes 4 and 5, and signals are input to the phase controller 8 to control the rotational phases of the centrifugal pumps 1 and 2. As a result, even when the centrifugal pumps 1 and 2 are operated in a wide range of rotation speeds, it is possible to reduce the generation level of fluid pulsation or reduce the vibration response of the structure due to pulsation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vortex pump pulsation suppressing device and method for suppressing a fluid pulsation generated in a centrifugal pump, piping connected to the centrifugal pump and a tank.

[0002]

2. Description of the Related Art Centrifugal centrifugal pumps have
A centrifugal pump 1 is known as shown in the cross-sectional view of FIG. 10 (a) and the front view of FIG. 10 (b). In this centrifugal pump 1, when the impeller 3 arranged in the spiral casing 2 is rotated by a drive source (not shown), the impeller 3 sucks fluid from the suction port 4 and pushes it out from the discharge port 5.

In this case, the blade 6 of the impeller 3 passes through the tongue portion (inlet) 8 of the discharge volute 7 to cause pulsation in the fluid. The fluid pulsation propagates through a piping system (not shown) connected to the casing 2 and causes vibration of the piping and the like.

A method for suppressing the propagation of the generated pressure pulsation to the piping system is to use a pipe or the like as an elastic pipe to absorb the fluid pulsation, or to provide a resonator in the pipe to utilize the interference of reflected waves to generate the pulsation. It is being canceled.

[0005]

In the method of suppressing the propagation to the piping system by using an elastic tube as the piping or providing a resonator, the fluid pulsation of a specific frequency is reduced when the centrifugal pump 1 is rotated at the rated speed. In most cases, the centrifugal pump 1 has little suppression effect when it is operated in a wide range of rotation speeds.

Further, in the method of reducing the fluid pulsation regardless of the rotation speed of the centrifugal pump 1, when the position of the existing centrifugal pump 1 is changed by changing the arrangement of the centrifugal pump 1 and the piping, There is a problem that it is often difficult due to various constraints.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to rotate a centrifugal pump in a wide range by canceling the pulsation by combining two centrifugal pumps and variably controlling the rotational speed of the centrifugal pump. It is an object of the present invention to provide a pulsation suppressing device for a centrifugal pump and a method thereof that can reduce the generation level of fluid pulsation or reduce the vibration response of a structure caused by pulsation even when operating in the speed range.

[0008]

According to a first aspect of the present invention, a first volute pump and a second volute pump are connected to a tank via pipes respectively, and a first volute pump side pipe is provided with a first volute pump. A pulsation sensor is attached, a second pulsation sensor is attached to the pipe on the side of the second centrifugal pump, and measurement signals from the first and second pulsation sensors are input to the first and second centrifugal pumps. It has a phase control device which outputs the output signal which controls a rotation phase to the 1st and 2nd centrifugal pump.

According to a second invention, in the first invention, the first and second vortex pumps are provided with first and second rotation angle sensors, respectively, instead of the first and second pulsation sensors. Mounting and controlling the phases of said first and second centrifugal pumps.

According to a third aspect of the present invention, a first centrifugal pump is connected to a first pipe, and a bypass pipe is connected to the first pipe located on the inlet side of the first centrifugal pump. To the first pipe and the bypass pipe, respectively, and a measurement signal from the first and second pulsation sensors is input to the first pipe and the bypass pipe. It has a phase control device which outputs an output signal for controlling the rotation phases of the first and second centrifugal pumps to the first and second centrifugal pumps.

A fourth aspect of the present invention is a method for suppressing pulsation of a volute pump in which a tip of a blade installed in an impeller crosses the tip of a tongue at the beginning of volute winding one after another as the blade rotates. It is characterized in that the pump is operated by varying the rotational speed of the pump so that the time interval across which it traverses is changed.

According to a fifth aspect of the present invention, in the fourth aspect, the rotational phase of the centrifugal pump is such that the tip of the blade of the first centrifugal pump crosses the tip of the volute tongue while the blade of the second centrifugal pump has the volute tongue. It is characterized by controlling so as to cross the tip.

According to a sixth aspect of the present invention, a plurality of centrifugal pumps are installed, and the direction or phase of the rotational speed fluctuation is adjusted between the respective centrifugal pumps so that the total amount of pumped liquid supplied by all the respective centrifugal pumps is adjusted. It is characterized in that the centrifugal pump is operated by changing the rotational speed of the centrifugal pump so as not to change.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, an inverter is used to control the rotation speed of the centrifugal pump, and the input voltage from the input transformer to the motor of the centrifugal pump is output by the inverter via the output converter. It is characterized in that it is changed in response to a signal from the pump speed controller.

An eighth aspect of the present invention uses an MG set to control the rotational speed of the centrifugal pump, and reduces the rotational speed of the electric motor by a fluid coupling in response to a signal from the speed controller to drive the AC generator. However, the rotation phase of the spiral pump motor is arbitrarily changed.

In a ninth aspect of the present invention, two systems of first and second circulation pipes are connected to the tank, and a volute pump is connected to each of the first and second circulation pipes. A control signal from a pressure sensor and a recorder and a pump rotation phase controller connected to the fluctuating pressure sensor is sent to an inverter or an MG set to phase control the rotation of the centrifugal pump.

A tenth aspect of the invention is characterized in that, in the ninth aspect, a pulsation sensor is attached to the pipe led out from the inside of the tank to the outside, and fluid pulsation in the pipe is measured by the pulsation sensor.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment (first embodiment) according to claim 1 of the present invention will be described with reference to FIGS. FIG. 1A is a coupling diagram with a pump piping system in the present embodiment, FIG. 1B is a waveform diagram showing a pulsation generation wave in FIG. 1A, and FIG. 1C is a waveform diagram showing a pulsation composite wave in FIG. 1B. Is.

In FIG. 1A, two pumps 1a, 1
Pipes 10 and 11 that join the tank 9 are connected to b. Fluid pulsation sensors 12 and 13 for measuring fluid pulsation are attached to the respective pipes 10 and 11. The fluid pulsation sensors 12 and 13 are connected to the input side of the phase control device 16 by the input side signal lines 14 and 15, and the output side of the phase control device 16 is connected to the pumps 1a and 1b by the output side signal lines 17 and 18. There is.

The signals from the sensors 12, 13 are phase control devices 16
Is taken into. The phase control device 16 receives the signals from the sensors 12 and 13 and outputs a signal for changing the rotational phases of the two pumps 1a and 1b. As shown in FIG. 1B, the fluid pulsation generation waves 19 and 20 are reversed. Control to be in phase. The fluid pulsation generation waves 19 and 20 having opposite phases of the two systems are superposed to form a pulsation synthetic wave 21 as shown in FIG. 1C, and the fluid pulsation is reduced.

Therefore, according to this embodiment, the two pumps 1a and 1b are arranged so that the fluid pulsations in the tank 9 have opposite phases.
It is possible to reduce the pulsation level by controlling the phase of the above and superimposing fluid pulsations having these opposite phases in the tank 9.

Next, an embodiment (second embodiment) according to claim 2 of the present invention will be described with reference to FIGS. 2, those parts which are the same as those corresponding parts in FIG. 1 are designated by the same reference numerals.
In this embodiment, the pipes 10 and 11 are attached to the pumps 1a and 1b, and the pipes 10 and 11 are attached so as to join the tank 9. Each pump 1a,
Rotation angle sensors 22 and 23 for measuring the rotation angle are attached to 1b. The signals from these sensors 22, 23 are
It is taken into the phase control device 16.

The phase controller 16 receives the signals from the sensors 22 and 23 as an input and outputs a signal for changing the rotational phase of the two pumps 1a and 1b to control the fluid pulsation to be in the opposite phase. By realizing fluid pulsations having opposite phases in the pipes 10 and 11 as shown in FIG. 2 (b), these are superposed to form a pulsation synthetic wave 21 as shown in FIG. 2 (c), and fluid pulsation is generated. It becomes possible to reduce.

According to this embodiment, the phase difference between the two pumps can be measured by the sensors 22 and 23 that measure the rotation angles of the pumps 1a and 1b. Based on the measured phase difference, the phases of the two pumps can be controlled so that the fluid pulsation is in the opposite phase.

Next, an embodiment (third embodiment) according to claim 3 of the present invention will be described with reference to FIG. This embodiment is applied to a low pulsation piping system, and the first pump 1c has a first
The second pipe 25 is attached to the first pipe 24 and is branched from the suction side of the first pump 1c of the first pipe 24 to bypass the second pipe 25.
Is connected. A second pump 1d is attached to the second pipe 25.

Fluid pulsation sensors 12 and 13 are attached to the suction sides of the pumps of the first and second pipes 24 and 25, respectively, and these fluid pulsation sensors 12 and 13 are connected to the phase controller 16 respectively.
To the input side signal lines 14 and 15. The phase controller 16 is connected to the first and second pumps 1c and 1d by output signal lines 17 and 18.

The signals from the fluid pulsation sensors 12 and 13 are taken into the phase controller 16. Phase control device 16 is the sensor
The signals from 12 and 13 are input to output signals for changing the rotational phases of the two pumps 1c and 1d, and the fluid pulsations in the pipes 24 and 25 are controlled to have opposite phases. According to the present embodiment, the plurality of pumps whose phases are controlled can reduce the pulsation level in the pipe due to the overlapping of the fluid pulsations of opposite phases in the pipe.

Next, an embodiment (fourth embodiment) according to claims 4 and 5 of the present invention will be described with reference to FIGS. 4A is a sectional view of the centrifugal pump 26, and FIGS. 4B and 4C are operation state diagrams of the centrifugal pump 26.

In the present embodiment, the vanes 28 constituting the centrifugal pump 26 are provided with the vanes 28 at equal intervals. Centrifugal pump
At 26, the blade tip 29 crosses the volute tongue tip 30 one after another during pump operation, causing blade cutting pulsation. As mentioned earlier, here the tips of the adjacent blades
Since the blade intervals 31 of 29 are arranged at equal intervals, the pulsation of the same cycle occurs in the pump operation at a constant rotation speed.

In this embodiment, as shown in FIGS. 4 (a) and 4 (b), a rotational speed varying operation 33 for changing the pump rotational speed from the target rotational speed 32 of the pump operation is performed. Therefore, the blade cutting pulsation generation interval also changes in accordance with the fluctuation of the pump rotation speed.

In the pump operation at a constant rotational speed at the target rotational speed 32 of the pump operation, the blade cutting pulsation generation interval is also constant, and this generation interval (cycle) coincides with the structure natural period 34 in which the blade cutting pulsation propagates. Then, it is considered that the structure resonates and the supporting portion of the structure is destroyed.

Here, since the rotational speed varying operation 33 for changing the blade cutting pulsation generation interval is performed, it is possible to give a phase difference between the dispersion of the blade cutting pulsation generation period and the generated blade cutting pulsation. Therefore, the resonance response of the structure due to the blade pulsation can be suppressed low.

In the present embodiment, the target rotational speed 32 of the pump operation is constant, but the rotational speed varying operation 33 is performed even in the operation stage in which the pumping liquid supply amount (flow rate) is increased or decreased. Similarly, the resonance response of the structure can be suppressed low.

According to this embodiment, the rotational speed of the pump 26 is varied so that the time intervals at which the blade tips 29 cross the volute tongue tips 30 one after another are changed. For this reason,
The pumped liquid sent to the vane 28 of the impeller 27 and discharged is collided with the tip 30 of the tongue at the beginning of volute winding, and the interval of the blade cutting pulsation generating pulsation is not constant.

Therefore, as compared with the case where the blade cutting pulsation occurs at a constant interval (single frequency) as in the prior art, the energy of the pulsation is dispersed into a plurality of frequencies and the pulsations of the same frequency component are distributed. Since a phase difference occurs due to the difference in pulsation occurrence time, the vibration level of the structure that resonates due to pulsation can be suppressed to a low level.

Next, an embodiment (fifth embodiment) according to claim 6 of the present invention will be described with reference to FIGS. FIG. 5A is a layout view of the centrifugal pump, and FIG.
(D) is an operation state diagram of the centrifugal pump.

In this embodiment, the centrifugal pump 1a and the centrifugal pump 1b are arranged so as to face each other, and the pumped liquid is supplied into the tank 9 through the pipes 10 and 11, or the pumped liquid is sucked from the tank 9. I'm out.

In the operation of the centrifugal pump 1a and the centrifugal pump 1b, as in the case of the fourth embodiment, the rotational speed varying operation for changing the blade cutting pulsation generation interval is performed, and the blade cutting pulsation generation cycle is dispersed. By giving a phase difference between before and after the generated blade cutting pulsation, the resonance response of the structure due to the blade cutting pulsation can be suppressed low.

In this case, the rotational speed fluctuation operation 35 of the centrifugal pump 1a and the rotational speed fluctuation operation 36 of the centrifugal pump 1b are reversed in rotational speed fluctuation phase [FIGS. 5 (b) and 5 (c)]. Therefore, the pumping liquid supply amount of the centrifugal pump 1a sent into the tank 9
The fluctuation phase of the pumping liquid supply amount 38 of 37 and the centrifugal pump 1b is reversed, and there is no fluctuation of the pumping liquid supply amount in the total supply amount 39 sent into the tank 9 (FIG. 5 (d)).

As described above, according to the present embodiment, even in the rotational speed varying operation, the rotational speed varying phases of the plurality of centrifugal pumps are adjusted between the pumps, so that the blade cutting pulsation can be obtained without changing the total supply amount. It is possible to suppress the resonance response of the structure to be low.

The direction or phase of the rotational speed fluctuation is adjusted between the pumps. When the rotational speed of the pump is changed, the pumping liquid supply amount (flow rate) is changed. In this embodiment, the direction or phase of the rotational speed change is adjusted between the pumps by a plurality of pump configurations. For example, in a two-pump configuration, the fluctuation direction of the rotational speed is reversed between pumps so as to cancel out fluctuations in the pumping liquid supply amount,
The pump can be configured so as not to fluctuate in the total amount of pumped liquid supplied, and the pumped liquid can be stably supplied.

Next, an embodiment (sixth embodiment) according to claim 7 of the present invention will be described with reference to FIGS. 6 (a) and 6 (b). FIG. 6A shows a control system by an inverter 40 of a pump showing a sixth embodiment according to claim 7 of the present invention, and FIG.
(B) is a characteristic diagram showing a time history change of the inverter frequency.

In the present embodiment, the inverter 40 is used to control the rotation speed of the centrifugal pump 1, and the motor of the pump 1 is changed from the input transformer 41 to the inverter 40 via the output transformer 43.
The input voltage to 44 is changed in response to the signal from the pump speed controller 42.

As shown in FIG. 6A, the frequency of the inverter 40 is increased by Δf at an arbitrary time Δtu, and the state is changed to Δth.
Hold for a period of time and return to the original frequency at the time of Δtd. This increases the pump speed from steady state and after holding it,
Can be undone. Also, from the first steady state, the inverter frequency rise width Δf and rise Δtu, hold Δth,
By controlling the fall time Δtd, the phase of rotation of the pump can be arbitrarily changed.

Next, an embodiment (seventh embodiment) according to claim 8 of the present invention will be described with reference to FIGS. 7 (a) and 7 (b). FIG. 7A is a pump control system by an MG set showing a seventh embodiment according to claim 8 of the present invention.
(B) is a characteristic diagram showing a time history change of the rake pipe position.

In this embodiment, the MG set is used to control the rotation speed of the centrifugal pump 1, and the rotation of the electric motor 45 is reduced by the fluid coupling 46 in response to a signal from the speed controller 47. The generator 48 is moved to change the rotation speed of the motor 49 of the pump 1.

The fluid coupling 46 has a structure in which an impeller rotated by the input shaft and a runner rotating the output shaft face each other, and there is no mechanical contact between the impeller and the runner. The fluid in the fluid coupling 46 is energized by the impeller and sent to the runner, which energizes the runner, loses velocity, and returns to the impeller again.

A part of the fluid is taken out of the fluid coupling 46 by the scooping tube, cooled outside, and conveyed again into the fluid coupling 46 by the pump 1. The fluid in the fluid coupling 46 is collected in the circumferential direction by centrifugal force during operation, but the fluid on the inner peripheral side of the fluid intake port of the rake pipe is in a state of being withdrawn to the rake pipe. Therefore, the amount of fluid in the fluid coupling 46 can be changed by changing the rake pipe position.

When the fluid coupling 46 is filled with fluid, the energy imparted to the fluid by the impeller is
Mostly consumed within the runner. Therefore, almost no slippage occurs between the input shaft and the output shaft. When the intake of the rake pipe is inserted in the outer peripheral direction in the joint and the amount of fluid in the fluid joint 46 is reduced, the ratio of energy consumed in the runner is reduced and the slip between the input and output shafts is increased.

The rake pipe position is changed by Δd at an arbitrary time Δtu, the state is held for Δth, and the original position is returned at the time of Δtd, whereby the pump speed is increased from the steady state and held, and thereafter, It is possible to return to the original state, and the phase of rotation of the pump can be arbitrarily changed by controlling the position change width Δd and the arrival Δtu, the holding Δth, and the return time Δtd of the rake pipe from the initial steady state.

Next, an embodiment (eighth embodiment) according to claim 9 of the present invention will be described with reference to FIG. FIG. 8 is a schematic cross-sectional view showing a partial block diagram of a system configuration for reducing fluid pulsation in a reactor in a reactor pressure vessel 56 showing an embodiment according to claim 9 of the present invention.

This embodiment is a reactor pressure vessel as a tank.
A fluctuating pressure sensor 50 is attached inside the device 56, and a pressure signal from the pressure sensor 50 is recorded in the recording device 51 as an input. Circulation piping of two systems as a centrifugal pump 5
The rotation speeds of the first and second recirculation pumps 53, 54 provided in 8, 59 are controlled to be the same, and by the phase controller 52, for example, based on the phase of the second recirculation pump 54, First
The phase of the recirculation pump 53 is changed from the initial value by 360 °.

The phase difference between the two pumps 53, 54 and the pressure fluctuation in the reactor pressure vessel 56 are recorded in the recorder 51, which detects the phase difference that minimizes the fluid pulsation, and the phase controller 52 A phase difference command signal is sent from the recorder 51, and the control signal is sent to the inverter 55 by the phase controller 52 to determine the phase of the pump first recirculation 53.

The detection of the optimum phase difference may be performed at an arbitrary time interval or when the rotation speed of the pump is changed. An MG set may be used instead of the inverter 55.

Next, an embodiment (ninth embodiment) according to claim 10 of the present invention will be described with reference to FIG. The present embodiment relates to a fluid pulsation measurement system, and in particular, a fluid pulsation sensor 62 is attached to a pipe 61 led out from the inside of the tank 60 to the outside. Water 63 is filled in the tank 60. The pipe 61 is connected to a centrifugal pump (not shown).

According to the present embodiment, the pipe 61 installed in the tank 60 causes vibration due to the fluid pulsation in the tank 60, and the fluid pulsation in the pipe 61 caused by this vibration is measured by the fluid pulsation sensor 62. The magnitude of fluid pulsation in the tank 60 can be measured.

[0057]

According to the present invention, the fluid pulsation in the tank is provided with an opposite phase by two pumps whose phases are controlled, and these are superposed to reduce the generation level of the fluid pulsation or to cause the pulsation. The vibration response of the structure can be reduced.

Conventionally, a pressure pulsation of a single frequency is generated by the rotation of the impeller, but the rotational speed of the pump is changed so that the time interval at which the tip of the blade crosses the tip of the volute tongue is changed. By performing the operation, the pulsation energy can be dispersed into a plurality of frequencies.

Further, by giving a phase difference between the pulsations of the same frequency component due to the difference in the pulsation occurrence time, the resonance response of the structure due to the pulsations can be suppressed low. Further, in a configuration in which the pumping liquid is supplied by a plurality of pumps, by giving a fluctuation phase difference of the rotation speed between the pumps in the rotation speed varying operation, the pumping liquid supply amount by the rotation speed varying operation is not changed. You can

[Brief description of drawings]

1A is a coupling diagram with a piping system of a pump for explaining a first embodiment of the present invention, FIG. 1B is a waveform diagram showing a pulsation generation wave in FIG. 1A, and FIG. The wave form diagram which shows the pulsation synthetic wave of (b).

2A is a coupling diagram with a piping system of a pump for explaining a second embodiment of the present invention, FIG. 2B is a waveform diagram showing a pulsation generation wave in FIG. 2A, and FIG. The wave form diagram which shows the pulsation synthetic wave of (b).

FIG. 3 is a connection diagram with a piping system of a pump for explaining a third embodiment of the present invention.

FIG. 4A is a cross-sectional view of a pump for explaining a fourth embodiment of the present invention, FIG. 4B is a waveform diagram showing the relationship between pump rotation speed and time, and FIG. 4C is a pulsation interval. FIG. 6 is a waveform diagram showing the relationship between time and time.

5A is a coupling diagram with a pump piping system for explaining a fifth embodiment of the present invention, FIG. 5B is a waveform diagram showing a relationship between pump rotation speed and time, and FIG. The wave form diagram which shows the relationship between pulsation generation intervals and time, (d) is a wave form diagram which shows the relationship between flow volume and time.

FIG. 6A is a block diagram for explaining a sixth embodiment of the present invention, and FIG. 6B is a waveform diagram showing the relationship between the inverter frequency and time in FIG.

7A is a block diagram for explaining a seventh embodiment of the present invention, and FIG. 7B is a waveform diagram showing the relationship between the rake pipe and time in FIG. 7A.

FIG. 8 is a schematic vertical sectional view showing a partial block for explaining an eighth embodiment of the present invention.

FIG. 9 is a schematic vertical sectional view for explaining a ninth embodiment of the present invention.

FIG. 10 (a) is a cross-sectional view showing a conventional centrifugal pump,
(B) is a front view of (a).

[Explanation of symbols]

1, 1a, 1b ... Volute pump, 2 ... Casing, 3 ... Impeller, 4 ... Suction port, 5 ... Discharge port, 6 ... Blade, 7 ... Volute, 8 ... Tongue, 9 ... Tank, 10, 11 ... Piping , 12, 13 ...
Fluid pulsation sensor, 14, 15 ... Input side signal line, 16 ... Phase control device, 17, 18 ... Output side signal line, 19, 20 ... Fluid pulsation generation wave, 21 ... Pulsation synthetic wave, 22, 23 ... Rotation angle sensor , 24 ... 1st
Pipe, 25 ... Second pipe, 26 ... Centrifugal pump, 27 ... Impeller, 28 ... Blade, 29 ... Blade tip, 30 ... Volute tongue tip, 31 ... Blade spacing, 32 ... Target rotation speed, 33 ... Rotation Number fluctuation operation, 34 ... Structure natural period, 35 ... Rotation speed fluctuation operation of spiral pump 1a, 36 ... Rotation speed fluctuation operation of spiral pump 1b, 37 ...
Pump supply amount of the centrifugal pump 1a, 38 ... Pump supply amount of the centrifugal pump 1b, 39 ... Total supply amount, 40 ... Inverter, 41 ... Input transformer, 42 ... Speed controller, 43 ... Output transformer, 44 ... motor,
45 ... Electric motor, 46 ... Fluid coupling, 47 ... Speed controller, 48 ... Alternator, 49 ... Motor, 50 ... Pressure sensor, 51 ... Recorder, 52
... Phase controller, 53 ... First recirculation pump, 54 ... Second recirculation pump, 55 ... Inverter, 56 ... Reactor pressure vessel, 57
… Jet pump, 58, 59… Circulation piping, 60… Tank, 61
… Piping, 62… Fluid pulsation sensor, 63… Water.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Katayama 1 Komukai Toshiba Town, Saiwai-ku, Kawasaki City, Kanagawa Prefecture Corporate Research & Development Center, Toshiba (72) Inventor Shinzo 8 Shinsugita-cho, Isogo-ku, Yokohama, Kanagawa Prefecture Address Incorporated company Toshiba Yokohama Works (72) Inventor Hiroshi Niwa Komukai-shi, Kawasaki-shi, Kanagawa 1 Komatsu Toshiba-cho Incorporated company Toshiba Research and Development Center (72) Inventor Yasuhiko Aida Komukai, Kawasaki-shi, Kanagawa Toshiba Town No. 1 Incorporated company Toshiba Research & Development Center (72) Inventor Yasushi Hattori No. 1 Komukai Toshiba Town, Kawasaki City, Kanagawa Prefecture

Claims (10)

[Claims] 1. A first vortex pump and a second vortex pump are connected to a tank via pipes, respectively, and a first pulsation sensor is attached to the pipe on the side of the first vortex pump, and the second vortex pump is attached. A second pulsation sensor is attached to the pump-side pipe, and measurement signals from the first and second pulsation sensors are input to output an output signal for controlling the rotation phase of the first and second centrifugal pumps. A pulsation suppressor for a centrifugal pump, comprising a phase control device for outputting to the first and second centrifugal pumps. 2. A first rotation angle sensor and a second rotation angle sensor are attached to the first and second centrifugal pumps instead of the first pulsation sensor and the second pulsation sensor, respectively. The pulsation suppressing device for a centrifugal pump according to claim 1, wherein the phase of the centrifugal pump is controlled. 3. The first volute pump is connected to a first pipe, and the first volute pump is located on the inlet side of the first volute pump.
A bypass pipe is connected to the pipe, a second centrifugal pump is attached to the bypass pipe, and first and second pulsation sensors are attached to the first pipe and the bypass pipe, respectively. It has a phase control device which inputs a measurement signal from a pulsation sensor and outputs an output signal for controlling the rotation phases of the first and second centrifugal pumps to the first and second centrifugal pumps. A pulsation suppressor for centrifugal pumps. 4. A method for suppressing pulsation of a volute pump in which a tip of a blade installed in an impeller of a centrifugal pump traverses a tongue tip at the beginning of volute winding one after another as the rotor rotates, wherein the tip of the vane successively touches the tip of the volute tongue. A method for suppressing pulsation of a centrifugal pump, which is operated by changing the rotational speed of the pump so that the time interval across the pump changes. 5. The rotational phase of the centrifugal pump is controlled so that the blade tip of the first centrifugal pump crosses the volute tongue tip in the middle while the blade tip of the second centrifugal pump crosses the volute tongue tip. The pulsation suppressing method for a centrifugal pump according to claim 4, which is characterized in that. 6. A plurality of centrifugal pumps are installed, and the direction or phase of the rotational speed fluctuation is adjusted between the respective centrifugal pumps to prevent fluctuation in the total amount of pumped liquid supplied by the total number of the respective centrifugal pumps. A method for suppressing pulsation of a centrifugal pump, which is characterized in that the centrifugal pump is operated while varying the rotational speed thereof. 7. An inverter is used to control the rotation speed of the centrifugal pump, and an input voltage from an input transformer to the motor of the centrifugal pump via an output converter by the inverter corresponds to a signal from a pump speed controller. 7. The pulsation suppressing method for a centrifugal pump according to claim 4, wherein the pulsation suppressing method is performed by changing the values. 8. An MG set is used to control the rotational speed of the centrifugal pump, the rotational speed of the electric motor is reduced by a fluid coupling in response to a signal from a speed controller, and the rotational speed of the AC generator is driven. 7. The pulsation suppressing method for a centrifugal pump according to claim 4, wherein the rotation phase of the pump motor is arbitrarily changed. 9. A fluctuating pressure sensor installed in the tank, wherein first and second circulation pipes of two systems are connected to the tank, and centrifugal pumps are connected to the first and second circulation pipes, respectively. A method for suppressing pulsation of a centrifugal pump, comprising sending a control signal from a recorder and a pump rotation phase controller connected to the fluctuating pressure sensor to an inverter or an MG set to control the phase of the rotation of the centrifugal pump. 10. The pulsation suppressing method for a centrifugal pump according to claim 9, wherein a pulsation sensor is attached to the pipe led out from the inside of the tank to measure the fluid pulsation in the pipe by the pulsation sensor. .